The district duchy, also known as the district principality, was a type of the state under the patrimonial system, such as duchy or principality, formed in the feudal system, as a result of land partition between the members of a royal family.[1] It occurred in the Middle Ages and early modern period, notably in Europe, in states such as the Holy Roman Empire,[2] Duchy of Poland,[1][3] and Kievan Rus'.[4]